title: Correlates and effect of suboptimal radiotherapy in women with ductal carcinoma in situ or early invasive breast cancer.
abstract: BACKGROUND
  The study aimed to identify factors associated with less-than-optimal radiotherapy (RT) and its impact on disease-free survival in women aged 66+ years diagnosed with stage I breast cancer or ductal carcinoma in situ (DCIS).
  
  
  METHODS
  The subjects were women diagnosed from 1991 to 1999 in the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database who underwent breast-conserving surgery and RT within 12 months postdiagnosis. The authors conducted descriptive and multivariate survival analyses, and considered age, race, poverty, marital status, comorbidity indices, rural/urban, radiation oncologist density, comedo necrosis histology (DCIS only), chemotherapy receipt (stage I only), and RT completion (3+ weeks of treatment) and delay (8+ weeks postsurgery without chemotherapy; 4+ weeks postchemotherapy).
  
  
  RESULTS
  Of 7791 subjects, 16% experienced RT delay, and 3% had incomplete RT. Subjects with stage I disease who were more likely to delay RT were of black race (odds ratio [OR], 1.56; 95% confidence interval [CI], 1.17-2.08), whereas women in areas of high radiation oncologist density were less likely to delay (OR, 0.73; 95% CI, 0.66-0.81). Those living in high poverty areas were less likely to complete RT (P < .03), as were those undergoing chemotherapy (OR, 1.82; 95% CI, 1.15-2.88). Stage I breast cancer patients with delayed RT were more likely to experience a subsequent breast event (OR, 1.14; 95% CI, 1.00-1.30), and those with incomplete RT had a higher rate of overall mortality (OR, 1.32; 95% CI, 1.06-1.63). Factors associated with lower subsequent breast events included older age, lower poverty, and being married. RT delays of 12+ weeks (or 8+ weeks postchemotherapy) had a strongly negative impact on subsequent events (OR, 3.94; 95% CI, 2.51-6.17 for DCIS; OR, 2.77; 95% CI, 1.84-2.59 for stage I).
  
  
  CONCLUSIONS
  RT should be facilitated to ensure completion and timeliness, especially for early invasive breast cancer patients.
authors.affiliation: Weill Cornell Medical College, New York, New York 10021, USA. heg2001@med.cornell.edu
authors.forename: Heather Taffet
authors.initials: HT
authors.lastname: Gold
authors.forename: Huong T
authors.initials: HT
authors.lastname: Do
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Dick
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D002278:Carcinoma in Situ / Q000532:radiotherapy; D018270:Carcinoma, Ductal, Breast / Q000401:mortality / Q000532:radiotherapy / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D015999:Multivariate Analysis; D011878:Radiotherapy / Q000379:methods*; D011879:Radiotherapy Dosage; D018426:SEER Program; D013997:Time Factors